Stop drinking if you do. Stop coffee after midday if you can. And go for a walk every night instead of sitting at your desk. Don't listen to music whilst you

Stop drinking if you do. Stop coffee after midday if you can. And go for a walk every night instead of sitting at your desk. Don't listen to music whilst you walk. You'll start to notice things, which will be interesting. After a few walks you'll be familiar with the environment. This will allow your mind to wander. Once you can get back a wandering mind, you'll find your imagination may come back, and you'll probably notice the exercise is helping with energy levels. After a while you'll find you like evening walks and you will be starting to think of a lot of stuff to do when you get home.